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NNDSS

The National Notifiable Diseases Surveillance System (NNDSS) is a nationwide collaboration that enables all levels of public health—local, state, territorial, federal, and international—to share notifiable disease-related health information. Public health uses this information to monitor, control, and prevent the occurrence and spread of state-reportable and nationally notifiable infectious and noninfectious diseases and conditions.

NNDSS is a multifaceted program that includes the surveillance system for collection, analysis, and sharing of health data. It also includes policies, laws, electronic messaging standards, people, partners, information systems, processes, and resources at the local, state, territorial, and national levels.

Supporting Public Health Surveillance in Jurisdictions and at CDC

Notifiable disease surveillance begins at the level of local, state, and territorial public health departments (also known as
jurisdictions). Jurisdictional laws and regulations mandate reporting of cases of specified infectious and noninfectious conditions
to health departments. The health departments work with healthcare providers, laboratories, hospitals, and other partners to
obtain the information needed to monitor, control, and prevent the occurrence and spread of these health conditions. In
addition, health departments notify CDC about the occurrence of certain conditions.

The CDC Division of Health Informatics and Surveillance (DHIS) supports NNDSS by receiving, securing, processing, provisioning,
and releasing nationally notifiable infectious diseases data to disease-specific CDC programs. DHIS also supports local, state, and
territorial public health departments in collecting, managing, and analyzing their data and in submitting case notification data to
CDC for NNDSS. DHIS provides this support through funding, health information exchange standards and frameworks, electronic
health information systems, and technical support. Together, DHIS and the CDC programs prepare annual summaries of
infectious and noninfectious diseases and conditions, which are published in the Morbidity and Mortality Weekly Report.

These programs collaborate with the Council of State and Territorial Epidemiologists (CSTE) to determine which conditions
reported to local, state, and territorial public health departments are nationally notifiable. The CDC programs, in collaboration
with subject matter experts in CSTE and in health departments, determine what data elements are included in national
notifications. Health departments participating in NNDSS voluntarily submit infectious disease data to DHIS and also submit
some data directly to CDC programs.

NNDSS Modernization Initiative

With the evolution of technology and data and exchange standards, CDC now has the opportunity to strengthen and modernize
the infrastructure supporting NNDSS. As part of the CDC Surveillance Strategy, the NNDSS
Modernization Initiative (NMI) is underway to enhance the system’s ability to provide more comprehensive, timely, and higher
quality data than ever before for public health decision making.

Through this multi-year initiative, CDC seeks to increase the robustness of the NNDSS technological infrastructure so that it is
based on interoperable, standardized data and exchange mechanisms.